1. Field of the Invention
The present invention relates to an endoscope operation portion structure including a frame inside thereof.
2. Description of the Related Art
Endoscopes are widely known, which can be introduced from an outside to an inside of a living body or construction in order to observe a site such as the inside of the living body or construction which is difficult to be observed. Such an endoscope generally includes an insertion portion provided so as to be continuous from an operation portion, and an observation window provided at a distal end portion of the insertion portion.
Observation, treatment and the like are performed by the endoscope such that a bending portion, or the like, provided at the insertion portion is operated to be bent in the state where the operation portion is grasped and the insertion portion is inserted into a site to be observed in a subject. Therefore, the operation portion from which the insertion portion is continuously provided is required to have a sufficient strength. For example, Japanese Patent Application Laid-Open Publication No. 11-192199 discloses an endoscope including a base plate as a frame for ensuring rigidity.
The base plate recited in the Japanese Patent Application Laid-Open Publication No. 11-192199 includes a stopper at a thick wall portion. The stopper is provided in order to prevent excessive load from being applied to an operation portion casing (also referred to as operation portion main body) when a holding portion casing (also referred to as grasping portion) of the operation portion is fixed, and prevent the base plate from being drawn out in a direction of the insertion portion.